Background .Simulation has been identified as an integrative strategy to bridge theory to practice and has been identified as a need in educating nurses in the future. There is no evidence in the nursing literature supporting the transfer of psychomotor skills learned through simulation to actual patient care. Errors in patient care are not permitted during practical hospital so Simulation-based education was emerging as alternative solutions to address this problem. The OSCE is a valid method for assessing students\' competence under a variety of simulated conditions. It is essential to evaluate critically how effective is the use of simulation in undergraduate nursing education. This research study will hopefully provide an unbiased answer to the latter issue. Aim. The aim of the present study is to evaluate the effect of low-fidelity simulation training with role play scenarios on nursing students clinical skills and ’ competence. Methods. A pretest/post-test randomized controlled design was employed with volunteer undergraduate students (n=260) from first year nursing students Faculty of Nursing Mansoura University students were assessed using a 10-station Objective Structured Clinical Examination(OSCE). Students were randomly allocated to either a control or an study group. The study group, as well as following their normal curriculum, were exposed to low fidelity simulation training. Subsequently, all students were re-tested after four months using an (OSCE). and completed a questionnaire. The data were collected between 2012and 2013. Results. There were a statistically significant increase in 2nd OSCE score in a study group than those in control group. On average a mean score (17.33 ± 1.72) & (14.27 ± 3.47) respectively. where p value < (0.001)? . As well there were a statistically significant improvement in performance between the two OSCEs for two groups. whereas the differences in improvement between the two groups were (4.84 ± 1.92) 95% CI for mean (4.51- 5.18 ) for the study group . And (0.70 ± 1.67) 95% CI for mean(0.41- 0.98) for the control group. The differences in improvement between the two groups were highly statistically significant p <0.001*.However, students’ perceptions of stress and confidence, measured on a 5-point Likert scale, was very similar between two groups. With no significant difference were detected between two groups (p= 0.742). Conclusions. The current results support the use of simulation in undergraduate nursing education. It is, however, important to recognize that it can only be beneficial to students if it is used appropriately and in a way that improves the quality of teaching and learning. Low -fidelity simulation with role play scenario is a useful training technique that improve student clinical skills and competency in a study group. It enables small groups of students to practise in a safe and controlled environment.